local param = require('comm.param')
local args = ngx.req.get_uri_args()
local black_ips = {["127.0.0.1"]=true}

local ip = ngx.var.remote_addr

if true == black_ips[ip] then
  ngx.exit(ngx.HTTP_FORBIDDEN)
  return
end

if not args.a or not args.b or not param.is_number(args.a, args.b) then
  ngx.exit(ngx.HTTP_BAD_REQUEST)
  return
end

